Goodwill Centenary Maxicard issued in 1986 (First day of issue for the stamp). Special Centenary postmark. Issued by the Historic relics with  industry year stamp. Rare first day maxicard. Not seen before. If set, this set & postmark has a very high value in the BFDC catalogue ( £120). Estimated value: £10 +. Here is the official FDC by the Historic Relics.